During a recent conference in Flagstaff, Ted Geisler, president of Arizona Public Service (APS), spoke to community representatives about the power company’s goal to transition fully to carbon-free energy production by 2050.
The plan includes heavy reliance on three key factors: nuclear energy, new technology and natural gas.
The push to go carbon free by 2050 in the state originated with a 2020 proposal from the Arizona Corporation Commission that would require a transition similar to what has been legislated in neighboring states such as Colorado and New Mexico. Despite initial bipartisan support, the proposal was modified, extended to a 2070 due date, but eventually voted down entirely by Republican utility regulators earlier this year.
Even so, APS has publicly declared themselves committed to the 2050 goal, including a full retirement of coal by 2031. According to Geisler, carbon-free energy resources are not only “the most affordable,” but within the “general interest” of society.
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“As the state's largest utility, we have an obligation to respond to what we're hearing our customers want,” Geisler said. “And that is that over time, we need to responsibly transition our power production fleet to be carbon free.”
Currently, APS generates 11,719 megawatts (MW) of power for Arizona, with 5,146 MW coming from nuclear, microgrid, and renewables such as solar and wind. The other 6,573 MW come natural gas and coal -- both of which contribute to carbon emissions.
In order to complete the carbon-free transition, APS will have to increase energy production among sources like nuclear and renewables. Nuclear energy, as embodied in the Palo Verde nuclear generating station, will be a key part of this transition, Geisler said.
“Palo Verde supplies 70% of our region's carbon-free energy today,” he reported. “It's the state’s single-largest taxpayer, is 100% carbon free and it's actually four times less carbon intensive than solar when you look at the end-to-end lifecycle of a resource.”
He added: “We will not achieve a carbon-free future without Palo Verde."
The mining of uranium in Arizona that fuels nuclear power has been a subject of controversy most recently addressed through the Grand Canyon Protection Act, which aims to ban uranium mining on over a million acres of federal land in northern Arizona. Regional bans like this wouldn’t affect APS, Geisler said.
“We don't depend on uranium being sourced from the local region to fuel Palo Verde,” he said.
He was unwilling to disclose the source of Palo Verde’s uranium, but claimed that they were “very supportive of continued uranium mining.” According to U.S. Energy Information Administration, in 2021 the U.S imported most of its uranium from Kazakhstan (35%), Canada (15%), Australia (14%), and Russia (14%).
Natural gas is the other “critical transition fuel,” Geisler said.
While not carbon free in itself, natural gas is “substantially reduced carbon compared to coal plants,” and, like nuclear, will help “enable reliability while introducing such high levels of new renewable technology onto the grid.”
Currently, APS generates 5,216 MW -- almost 45% of its total energy -- from natural gas.
One of the reasons natural gas is such an important resource in energy production is that its “flexible” Geisler said, meaning that APS can use it as a “shock absorber” as demands on the power grid fluctuate.
“Were relying on it [natural gas] a lot right now as we retire from coal and build out our clean portfolio,” Geisler said. “But it's going to be critical over this period to maintain reliability.”
The final piece of the puzzle is new technology that will help renewable sources function on a larger, more reliable scale, Geisler said.
A key example is the widespread implementation of battery storage systems that can store solar energy to reliably supply the power grid with soar energy even after the sun sets.
“By the end of this year, we will have about 300 megawatts of new storage on the grid,” Geisler said. “And we expect that by the end of the decade, that number will grow to close to 3,000. Storage is becoming more and more affordable.”
New technology is also part of what Geisler called “the nuclear renaissance.”
“I don't ever see another large-scale nuclear power plant like Palo Verde being built again,” Geisler said. “But there's a lot of interest and investment in small-scale nuclear, small modular reactors, what we call SMR’s.”
According to Geisler, SMR’s can be mass produced, easily shipped and can produce 400-500 MW each.
“It can be a beautiful technology for us in the future,” he said, adding that nuclear SMR’s would not “displace” renewables but contribute to a “diverse portfolio” of carbon-free energy sources.
Even natural gas is up for a technological re-vamp, said Geisler.
Existing natural gas facilities could potentially be modified to run on hydrogen.
“We have partnered with Idaho National Labs and other utilities, and we're developing a small-scale hydrogen production facility in southern Arizona,” Geisler said. “The intent is to explore how using a hydrogen fuel source works in a natural gas fleet.”
Promising as new tech might be, don’t expect APS to be on the bleeding edge, Geisler said. In some cases, such as with SMR’s, he said he expects to wait “8-10 years” to let other firms develop and implement new tech.
“Candidly, Arizona is not big enough to take risks on new technology like that,” Geisler said. “We don't want to put your dollar at risk for that either.”
Rather than a risk, the technology to support carbon-free energy is already quite established, said Tom Acker, director of the Sustainable Energy Solution Group at Northern Arizona University.
Transitioning by 2050 is “very doable,” Acker said.
“The technologies there actually already exist in a form that could work,” he said. “The utilities just don't have much operational experience with these. They need to gain experience and confidence.”
Acker also mentioned that while technological advances in nuclear — such as SMR’s — may be entering an affordable and functional future, the industry still largely doesn’t have a solution for the waste.
Nuclear waste can remain hazardous for thousands of years, Acker said, and that should be a concern.
“It's not necessarily the economics of nuclear power that is going to be its main challenge,” he said. “The main challenge is wherever it gets implemented. Since we don't have a long-term depository, the waste is going to be on-site. So whatever waste a nuclear site produces, it is probably going to have to store it indefinitely.”
Taking a lead
Not only does the tech exist, Arizona has the potential to be a “global leader” in renewable solar energy, said Karla Morales, vice president of the Arizona Technology Council southern regional office.
For Morales, not only does Arizona have “an abundant natural resource” in sunlight, but it has the university-level research initiatives, technical capabilities within utility companies, and “high demand for energy to grow our homes and buildings as well as growing the electric vehicle market.”
“I think we have the perfect setting,” Morales said. “We really could be a leader in solar power.”
So perfect is Arizona’s natural and technological setting, Morales said, the APS timeline of going carbon free by 2050 is “reasonable” but she would “urge that we move a little bit faster.”
The ramifications of moving the carbon-free transition forward at a more rapid pace could be “massive,” Morales said, “for job creation, for local economy growth. There’s just a great deal of opportunity.”